Math Problem Statement

Given that \( \frac{\left( (2p^3q^4)^4 \div (-3q^5)^2 \right)}{9} \div \left( (4p^2q)^2 \right) = \frac{p^{a+b}}{q^{a-b}} \), form a pair of simultaneous equations in \( a \) and \( b \) and hence find the value of \( a \) and \( b \).

Solution

To solve the given problem, we need to simplify the left-hand side and equate it to the given right-hand side pa+bqab\frac{p^{a+b}}{q^{a-b}}. We will then extract simultaneous equations to determine aa and bb.


The Problem:

((2p3q4)4÷(3q5)2)9÷((4p2q)2)=pa+bqab.\frac{\left( (2p^3q^4)^4 \div (-3q^5)^2 \right)}{9} \div \left( (4p^2q)^2 \right) = \frac{p^{a+b}}{q^{a-b}}.


Step 1: Simplify the numerator

The numerator is: ((2p3q4)4÷(3q5)2).\left( (2p^3q^4)^4 \div (-3q^5)^2 \right).

  • First, simplify (2p3q4)4(2p^3q^4)^4: (2p3q4)4=24(p3)4(q4)4=16p12q16.(2p^3q^4)^4 = 2^4 \cdot (p^3)^4 \cdot (q^4)^4 = 16p^{12}q^{16}.
  • Next, simplify (3q5)2(-3q^5)^2: (3q5)2=(3)2(q5)2=9q10.(-3q^5)^2 = (-3)^2 \cdot (q^5)^2 = 9q^{10}.
  • Now divide: (2p3q4)4(3q5)2=16p12q169q10=16p129q1610=16p12q69.\frac{(2p^3q^4)^4}{(-3q^5)^2} = \frac{16p^{12}q^{16}}{9q^{10}} = \frac{16p^{12}}{9} \cdot q^{16-10} = \frac{16p^{12}q^6}{9}.

Step 2: Divide by 9

Next, divide the result by 99: 16p12q699=16p12q681.\frac{\frac{16p^{12}q^6}{9}}{9} = \frac{16p^{12}q^6}{81}.


Step 3: Simplify the denominator

The denominator is: (4p2q)2.(4p^2q)^2. Simplify: (4p2q)2=42(p2)2q2=16p4q2.(4p^2q)^2 = 4^2 \cdot (p^2)^2 \cdot q^2 = 16p^4q^2.


Step 4: Combine numerator and denominator

Now divide the simplified numerator by the denominator: 16p12q68116p4q2.\frac{\frac{16p^{12}q^6}{81}}{16p^4q^2}.

  • Simplify the constants: 1681÷16=181.\frac{16}{81} \div 16 = \frac{1}{81}.
  • Simplify the powers of pp and qq: p12÷p4=p124=p8,q6÷q2=q62=q4.p^{12} \div p^4 = p^{12-4} = p^8, \quad q^6 \div q^2 = q^{6-2} = q^4. Thus: 16p12q68116p4q2=p8q481.\frac{\frac{16p^{12}q^6}{81}}{16p^4q^2} = \frac{p^8q^4}{81}.

Step 5: Equate to the given expression

We are given: p8q481=pa+bqab.\frac{p^8q^4}{81} = \frac{p^{a+b}}{q^{a-b}}.

  • Comparing the powers of pp: a+b=8.a + b = 8.
  • Comparing the powers of qq: (ab)=4    ab=4.-(a - b) = 4 \quad \implies \quad a - b = -4.

Step 6: Solve the simultaneous equations

We now solve:

  1. a+b=8a + b = 8,
  2. ab=4a - b = -4.

Add the two equations: (a+b)+(ab)=8+(4)    2a=4    a=2.(a + b) + (a - b) = 8 + (-4) \implies 2a = 4 \implies a = 2. Substitute a=2a = 2 into a+b=8a + b = 8: 2+b=8    b=6.2 + b = 8 \implies b = 6.


Final Answer:

The values of aa and bb are: a=2,b=6.\boxed{a = 2, \, b = 6.}


Let me know if you need a detailed explanation of any step!

Here are 5 related questions for practice:

  1. Simplify (3p2q)3÷(9pq4)(3p^2q)^3 \div (9pq^4).
  2. Solve for xx and yy if x+y=10x + y = 10 and xy=2x - y = 2.
  3. Simplify (2a3b2)24a4b\frac{(2a^3b^2)^2}{4a^4b}.
  4. Evaluate (p2q3)4p8q12\frac{(p^2q^3)^4}{p^8q^{12}}.
  5. Solve x2=42÷2x^2 = 4^2 \div 2.

Tip: When dividing powers of the same base, subtract the exponents!

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Math Problem Analysis

Mathematical Concepts

Exponents and Powers
Simultaneous Equations
Simplification of Algebraic Expressions

Formulas

Power of a Power: \( (x^m)^n = x^{mn} \)
Division of Exponents: \( \frac{x^m}{x^n} = x^{m-n} \)
Laws of Exponents for Products: \( (ab)^n = a^n b^n \)

Theorems

Laws of Exponents

Suitable Grade Level

Grades 9-10