Question

Hi can u guys help me please
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Answer 1

1. a.) The x intercepts are 7 and negative 3.

b.) The y-intercept is -21

2. C

3. a.) 4

b.) 4 and 1

Explanation:

1 a.)The x intercepts can be found by setting y to 0, and solving for x for each factor individually.

0=x-7

7=x

0=x+3

-3=x

b.)The y-intercept can be found by multiplying the factors and looking the stand-alone number at the end of the equation. This can also be solved mathematically by replacing the x's in the equation with 0.

`y=(x-7)(x+3)\\y=x^2-7x+3x-21\\y=x^2-4x-21\\y=(0)^2-4(0)-21\\y=-21`

2.) Based on the graph we can see the line intercepts the x-axis at -1 and 3. So if we were to put this into factored form, the numbers would be opposite when paired with x. Hence

(x-3)(x+1)

3 a.) Again, this can be found by observing the number by itself at the end of the equation or mathematically by changing x to 0

`y=(0)^2-5(0)+4\\y=4`

b.) As stated previously, this can be found by setting the y to 0 and solving the factors.

`0=(x-4)(x-1)\\0=(x-4)\\4=x\\0=x-1\\1=x`