Easy, showing work,
using the method FOIL (First,Outer,Inner, Last)
Take, (x+3)(x+5) and multiply,
First,
x*x=

Outer,
x*5=5x
Inner,
3*x=3x
Last,
3*5=15
Add the terms together,

+8x+15 (

+5x+3x+15)
Thus, your answer.
I=1.5m
m+1.5m=20
2.5m=20
m=8
20-8=12
Isobel worked 12 hours.
B. Add -12x to both sides. Then divide all terms by -2. The positive 12 on the right side will be a -6 and the -42 will be a positive 21. The inequality sign is always switched whenever the equation is divided by a negative number.
Y-3=-5/3(x-8)
Y-3= -5/3x + 13 1/3
Y = -5/3x + 13 1/3 + 3
Y = -5/3 + 16 1/3
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