Question

the area of the rectangle is 48cm^2
show that x satisfies the equation x^2 + 7x -78 = 0

Answer 1

Answer:

No its doesn't satisfy the equation.

${ \bf{area = 2(l + w)}} \\ { \tt{48 = 2((x + 10) + (x - 3))}} \\ { \tt{24 = 2x + 7}} \\ 2x = 17 \\ x = 8.5 \\ \\ { \bf{in : \: {x}^{2} + 7x - 78 = 0 }} \\ x = 6 \: \: and \: \: - 13$