William W. answered • 03/14/21
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The way the problem is written it's hard to tell whether this is supposed to be 5 times the cube root of 40 and 9 times the cube root of 135 or if it's 5 cubed times the square root of 40 and 9 cubed times the square root of 135. I'm GUESSING it is 5•(cube root(40)) + 9•(cube root(135))
cuberoot(40) = cuberoot(8•5) = 2cuberoot(5) so 5cuberoot(40) = 5•2cuberoot(5) = 10cuberoot(5)
cuberoot(135) = cuberoot(27•5) = 3cuberoot(5) so 9cuberoot(135) = 9•3cuberoot(5) = 27cuberooot(5)
10cuberoot(5) + 27cuberooot(5) = 37cuberoot(5) so a = 37 and b = 5
