URGENT! tolong jawab nomor 7&8 dengan caranya, terima kasih.

7.
2x²-9x+10 = 0
x²-(9/2)x + 5 = 0
x² - 2(9/4)x + (9/4)² - 1/16 = 0
(x-(9/4))² = 1/16
(x-(9/4)) = ±1/4
x1 = 2
x2 = 5/2

8.
ax² + bx + c = 0
misal x1,x2 adalah akar2nya
x1+x2 = -b/a
x1.x2 = c/a

x1+x2 = 3/4 + -4 = -13/4
x1.x2 = 3/4.-4 = -3
jdi dpat dibuat persmaan misal a = 1
x²+bx+c = 0
-b/1 = x1+x2
b = 13/4
c/1 = x1x2
c = -3
persmaan kuadratnya
x²+(13/4)x + (-3) = 0
4x²+13x-12=0