No 4 5 6 pake cara makasih yg udah jawab

4) 2x²+2 = x²+3x
2x²-x²-3x+2 = 0
x²-3x+2 = 0

5) 2x²-5x-3 = 0
2x²-6x+x-3 = 0
2x(x-3)+(x-3) = 0
(2x+1)(x-3) = 0
2x+1 = 0. Dan x-3 = 0
2x = -1. x = 3
x = -½

6) a+ b = 12 —> a = 12-b
ab = 35

(12-b) b = 35
12b-b² = 35
b²-12b+35 = 0
b²-7b-5b+35 = 0
b(b-7)- 5(b-7) = 0
(b-5) (b-7) = 0
b = 5. atau b = 7

a = 12-b. Atau a= 12-b
= 12-7. = 12-5
= 5. = 7