I think the answer is c beacause you have to multiply to get the answer
Answer:
See the attached figure which represents the problem.
As shown, AA₁ and BB₁ are the altitudes in acute △ABC.
△AA₁C is a right triangle at A₁
So, Cos x = adjacent/hypotenuse = A₁C/AC ⇒(1)
△BB₁C is a right triangle at B₁
So, Cos x = adjacent/hypotenuse = B₁C/BC ⇒(2)
From (1) and (2)
∴ A₁C/AC = B₁C/BC
using scissors method
∴ A₁C · BC = B₁C · AC
4<√19<5
8<√77<9
so the quality numbers are 5,6,7,and 8
5+6+7+8=26
so the answer is 26
Your equation would be 2x - 12 + 3x - 15 = 23
Combine like terms and solve for x