Question

Let ​ x² + 15x = 49 .​

Answer 1

$x^{2} +15x+56.25=49$

Answer 2

$x^{2} + 15x = 49$

for completing the squares , we have to add both sides the square of half of coefficient of x

So we add both sides $(\frac{15}{2} )^{2}$

or

$(7.5)^2$

$x^{2} + 15x + (7.5)^2 = 49 +(7.5)^2$

$x^{2} + 15x +56.25 = 105.25$

So these values will make it equivalent for completing the squares