Practicing Success
If $x^2+9 y^2+4 z^2=12(x-2 y+2 z)-88$, then the value of $(x-3 y+z)$ is: |
11 13 10 5 |
13 |
If $x^2+9 y^2+4 z^2=12(x-2 y+2 z)-88$ Make the above equation in the form of a2 + b2 + c2 = (a + b + c)2 - 2(ab + bc + ac) $x^2+9 y^2+4 z^2= 2(6x- 12y+12z)-88$ we can find the values of the variables by = Coefficient of variables on right sides divide by coefficient of same variable on left side along with the signs as given below = x = 6 4 = -\(\frac{12}{9}\) c = \(\frac{12}{4}\) = 3 $(x-3 y+z)$ = (6 -3 × (-\(\frac{12}{9}\)) + 3) = 13 |