Question

Which equations are true for x = –2 and x = 2? Check all that apply.

A.x2 – 4 = 0
B.x2 = –4
C.3x2 + 12 = 0
D.4x2 = 16
E.2(x – 2)2 = 0

Answer 1

А. х²-4=0; х²=4; х=±2, true. B. x²=-4; there is no solution. C. 3x²+12=0; 3x²=-12; x²=-4; there is no solution. D. 4x²=16; x²=4; x=±2, true. E. 2(x-2)²=0; 2(x²-4x+4)=0; 2x²-8x+8=0; x²-4x+4=0; x1=2; x2=2. False. The answer: A, D.