Ok so remember
order of simplification
PEMDAS
parenthaseese
exponents
multiplicaton or division whichever comes first
addition or subtraction whichever comes first
ok so remmeber work from the left to right parenthasees first and work from inside to outer parenthasees
so first one
innermost parenthasees first so
first step is 2-4
subtract 4 from 2
second one
if xy=0 then assume x and y=0 so
(a+2)(b-9)=0
a+2=0
a=-2
b-9=0
b=9
so answe ris a=-2
b=9
third questions
innermost parenthaees first
subtract 4 from 2
ok
1. subtrac 4 from 2
2. a=-2, b=9
3. subtract 4 from 2
It is a good idea to check to see if your answer is reasonable because a. if your answer is reasonable, you have probably done the problem correctly.
Just do for example on number 38 you will do 6.8/1000= 0.0068 which is the answer
Divide 28 by 4 which is 7 and then times that number by 9 so 63 windows im pretty sure
