Question

A) x²-90 =31
B) 5 x²+4=49
C) 4 x²-27= x²
D) 2 x² +11= x²+12
E) 5( x²-1) 4 ( x²+1)
F) x(x+2)=2x +25

Answer 1

a) x^2 - 90 = 31 x^2 = 31=90 x^2 = 121 x =√121 x = 11

 b)  5x^2 + 4 = 49 5x^2 =49-4 5x^2 = 45 x^2 =45÷5 x^2 = 9  x = √9 x = 3

c) 4x^2 - 27 = x^2  4x^2 -27-x^2 3x^2= 27 x^2 = 27/3 x^2 =9 x= √9 x = 3

 d) 2 x² +11= x²+12

2x^ - x^2 = 12 - 11

x^2 =1

x = 1

e) 5(x^2 -1) = 4(x^2 + 1)

5x^2 - 5 = 4x^2 + 1

x^2 = 6

x = √6

f) x(x+2) = 2x+ 25

x^2 + 2x =2x + 25

x^2 = 25

x = √25

x =5

6x^2