Answer:
a=8
Step-by-step explanation:
Since this is a right triangle, we can use the Pythagorean theorem
a^2 +b^2 = c^2 where a and b are the legs and c is the hypotenuse
a^2 +15^2 = 17^2
a^2 +225 = 289
Subtract 225 from each side
a^2 +225-225=289-225
a^2 = 64
Take the square root of each side
sqrt(a^2) = sqrt(64)
a = 8
Answer: the answer is 7
Step-by-step explanation: add 9 to both sides, eliminating -9 so now you have 7x=49 divide both by 7 and you get x= 7 check it by inputing 7 for x, 7(7)-9=40
7(7)=49 next 49-9= 40
it checks out, so x= 7
