Keri is simplifying 5·10−3.

which could be the first step to use when simplifying the expression?
a) 5 · 10−3 = 5(10)^1/3
b) 5 · 10−3 = 1/50^3
c) 5 · 10−3 = 1/50^1/3
d) 5 · 10−3 = 5(1/103)

I think its C)... I might be wrong though, I'm sorry if I am...

let soccer = x and golf = y

part a

1st equation: x + y = 125

2nd equation: x = y +45

part b

replace x in the 1st equation with the 2nd one:

y + 45 + y = 125

simplify:

2y + 45 = 125

subtract 45 from each side:

2y = 80

divide both sides by 2:

y = 80/2

y = 40

she plays golf for 40 minutes.

part c

no because she plays soccer for 45 minutes longer than golf 40 +45 =   85 minutes, not 80 minutes.