Given y=-3x^2=8x+35 answer the following questions

Question

Find the x-intercepts by factoring

Answer 1

y = -3x² - 8x + 35

 

The x-intercepts occur where y = 0:

 

0 = -3x² - 8x + 35

 

Factors to:

 

0 = (-3x+7)(x+5)

 

x = 7/3 and -5

Answer 2

The x-intercept occurs when y = 0.

 

0 = -3x² - 8x + 35

0 = -(3x² +8x - 35)

0 = -(x + 5)(3x - 7)

 

Either

x + 5 = 0

x = -5

 

Or

3x - 7 = 0

3x = 7

x = 7/3

 

x ∈ { -5, 7/3 }