Question

a) x^2=1
b) x^2=81
c) 4x^2=1
d) 2x^2=8
e)x^2=4
f)5x^2=20
g) (x-1)^2=9

Answer 1

a) x²=1 => x=±1;

b) x²=81 => x=±9;

c) 4x²=1;

x²=1/4;

x=±1/2;

d) 2x²=8;

x²=8/2;

x²=4;

x=±2;

e) x²=4 => x=±2;

f) 5x²=20;

x²=20/5;

x²=4;

x=±2;

g) (x-1)²=9;

x²-2x+1=9;

x²-2x+1-9=0;

x²-2x-8=0;

delta=4+32=36;

x1,2=(2±6)/2;

x1=4;

x2=-2;