Let's solve the tasks visible in the image step by step:

1. Task

a) Which equation is quadratic?

Quadratic equations are of the form $ax^2 + bx + c = 0$, where $a \neq 0$. Let's analyze the options:

• A) $5x - 1 = 0$: This is a linear equation (no $x^2$ term).
• B) $2x^2 + 4x = 0$: This is a quadratic equation.
• C) $3x + 5x = 0$: This is a linear equation.
• D) $x - 2^2 = 0$: No $x^2$ term; this is also linear.

Answer: B) $2x^2 + 4x = 0$

b) Write the coefficient $a$ for the quadratic equation $2x^2 - 7x + 1 = 0$.

In the equation $2x^2 - 7x + 1 = 0$, the coefficient $a$ is the number in front of $x^2$, which is $a = 2$.

Answer: $a = 2$

c) Which equation has the coefficients $a = 2$, $b = 3$, and $c = 4$?

We need to find the equation of the form $2x^2 + 3x + 4 = 0$. Let's analyze the options:

• A) $2x^2 + 4x + 3 = 0$: Incorrect coefficients.
• B) $4x^2 + 2x + 3 = 0$: Incorrect coefficients.
• C) $3x^2 + 2x + 4 = 0$: Incorrect coefficients.
• D) $2x^2 + 3x + 4 = 0$: Correct coefficients.

Answer: D) $2x^2 + 3x + 4 = 0$

2. Task

Mark 3 quadratic equations:

Quadratic equations follow the form $ax^2 + bx + c = 0$, where $a \neq 0$ and $x^2$ is present.

• A) $x^2 - 49 = 0$: This is a quadratic equation.
• B) $x^2 + 3x + x^3 = 0$: Not quadratic (has an $x^3$ term).
• C) $(x^2 - 4)(x + 4) = 0$: This can be expanded into a quadratic equation.
• D) $x(x + 7) = 0$: This is quadratic (can be written as $x^2 + 7x = 0$).
• E) $(x + 5)^2 = 0$: This is a quadratic equation (expands to ( x^2 + 10x + 25 = 0 \