I think it's 60 I'm NOT sure. I just multiplied those three numbers
298 times 6 is 1788 idk what you mean by friendly numbers
Find two numbers that multiply to -30 (last term) and add to 7 (middle coefficient)
The two numbers are 10 and -3
10 times -3 = -30
10 plus -3 = 7
Using those two values gets us the two factors (y+10) and (y-3)
Therefore, y^2+7y-30 factors to (y+10)(y-3)
The equation y^2+7y-30 = (y+10)(y-3) is true for all values of y.
Answer:
x = 2/5 or x = -2/3
Step-by-step explanation:
y = x - 2
z = 2y = 2(x - 2) = 2x - 4
4x² = (3y - 5z ÷ 4)²
Substitute y with x - 2. Substitute z with 2x - 4.
4x² = [3(x - 2) - 5(2x - 4) ÷ 4]²
16 * 4x² = [3(x - 2) * 4 - 5(2x - 4) ÷ 4 * 4]²
64x² = [12(x - 2) - 5(2x - 4)]²
64x² = (12x - 24 - 10x + 20)²
64x² = (2x - 4)²
64x² = 4x² - 16x + 16
60x² + 16x - 16 = 0
15x² + 4x - 4 = 0
ac = 15 * (-4) = -60
-6 * 10 = -60
-6 + 10 = 4
15x² - 6x + 10x - 4 = 0
(15x² - 6x) + (10x - 4) = 0
3x(5x - 2) + 2(5x - 2) = 0
(5x - 2)(3x + 2) = 0
5x - 2 = 0 or 3x + 2 = 0
5x = 2 or 3x = -2
x = 2/5 or x = -2/3
