The slant height, x, is 7.5 mm because you use the pythagorean formula and solve for c, since the you're solving for the hypotenuse which is the longest side.
Step-by-step explanation:
5x-12=13
5x -12 =13
+12=+12
<u>5x</u>= <u>25</u>
5 =. 5
x=5
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X2 - 25 = 0
Add 25 on each side.
x2 = 25
Divide by 2 on each side.
x = 12.5