Question

What are the x-intercepts of the graph pf the function below? y=x^2+3x=28

Answer 1

To solve this, you need to subtract 28 from both sides, then solve.

y=x^2+3x-28

The x-intercepts are (-7,0) and (4,0)

Answer 2

Answer:  The required x-intercepts are (4, 0) and (-7, 0).

Step-by-step explanation:  We are given to find the x-intercepts for the parabola defined by the following equation :

$y=x^2+3x-28~~~~~~~~~~~~~~~~~~~~~~~~~(i)$

We know that

the x-intercepts of a function are the points where the y co-ordinate is zero.

So, from equation (i), we have

$y=0\\\\\Rightarrow x^2+3x-28=0\\\\\Rightarrow x^2+7x-4x-28=0\\\\\Rightarrow x(x+7)-4(x+5)=0\\\\\Rightarrow (x-4)(x+7)=0\\\\\Rightarrow x-4=0,~~~x+7=0\\\\\Rightarrow x=4,~-7.$

Therefore, the x-intercepts of the given function are (4, 0) and (-7, 0).