Question

ok who can help with this problem ill post the link to it I calculated -5 and so did the person who was helping me with my work but the software my school uses marks this answer as wrong

Answer 1

cross multiply (x+5)(x+7) = (x-4)(x-5)
distribute/foil x^2 + 5x + 7x + 35 = x^2 - 5x - 4x + 20
add like terms x^2 + 12x + 35 = x^2 - 9x + 20
subtract x^2 from both sides 12x + 35 = -9x + 20
add 9x to both sides 21x + 35 = 20
subtract 35 from both sides 21x = -15
divide both sides by 21

Answer 2

ok thanks