{x+2} =8 which of the following is the solution set for the equation
a) {6,6{
b){6,-10}
c) {6,6}
d) {-6, 10}
which one is the answer
{x+2} =8 which of the following is the solution set for the equation
a) {6,6{
b){6,-10}
c) {6,6}
d) {-6, 10}
which one is the answer
I think the curly bracket { is a modulus written like |
Questions of this type will have two solutions as indicated in the solution choices.
Remember that modulus changes negative to positive values.
1st solution: put a negative sign around (x+2) and solve
-(x+2) = 8
taking negative into the parenthesis,
-x -2 = 8
i.e. - x = 10 or x = -10
2nd solution: solve with the positive sign around (x+2)
x+2 = 8 i.e. without the negative sign
x = 8 - 2 = 6
so solution b) ( 6,-10) is the right answer.
The other approach is to squaring method;
Square both sides of the equation:
(x+2)^2 = 8^2
x^2 + 4x + 4 = 64
bringing 64 to the left of the equation,
x^2 + 4x - 60 = 0
Factorizing the above equation
x^2 + 10x - 6x - 60 = 0
(x+10) (x-6) = 0
x+10 = 0 or x = -10
or
x - 6 = 0 or x = 6
Again, b) is the right answer (6, -10)