Using the converse of Pythagorean Theorem and the law of sines and cosines solve the word problem.

It's the law of cosines

Step-by-step explanation:

law of cosines states that

so we know that a = 7, b = 4, and alpha would be 135 degrees, so just plugging it in gets us 49+16-2*7*4*(-0.707) = 65 + 39.59 = 104.59

problem:

f(x) = - 2/3x + 5; f(5/2)

substitute 5/2 in for x:

f(5/2) = -2/3(5/2) + 5

simplify the right side:

f(5/2) = -5/3 + 5

f(5/2) = 10/3

f(5/2) = 10/3

i hope this !