Find the sum of \left(7x^3-3x^2\right)(7x 3
−3x
2
) and \left(2x^3-5x^2\right)(2x
3
−5x
2
)

9x^3-8x^29x
3
−8x
2

5x^35x
3

9x^3+2x9x
3
+2x

5x^3-8x^25x
3
−8x
2

\left(7x^3-3x^2\right)(7x3−3x2) =15x\left(7x^3-3x^2\right)

\left(2x^3-5x^2\right)(2x3−5x2)9x^3 8x^29x3−8x25x^35x39x^3+2x9x3+2x5x^3-8x^25x3−8x2 =-39000x^8-72x^7+180x^6+10x^4-336x^3+54x^2-16x

1/5^2 = 7.56/45

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15