To write the number is standard form we need to move the decimal point six times to the right, then:

therefore the answer is b.
Complementary angles add up to 90 degrees.
Which means.. the equation is
8x-23+7x-7=90
Combine like terms you should get
15x-30=90
Add 30 on both sides
15x=120
Divide 15 x=8
Plug in 8 to (8x-23)
8(8)=64-23=41
m
Find the base price per pound, $15/11, or $1.36 = 1lb, then multiply it by 16, 16 x 1.36 = $21.82. Now just subtract $20 from $21.82 = $1.82. So, You would save, on average, $1.82 by buying the sale.
If you want to translate the phrase 30 added to a number that is decreased by 5 into a math expression, you can do it like this:
a number ... n
30 added ... + 30
decreased by 5 ... - 5
Now you just have to put this together: n + 30 - 5 or n - 5 + 30. So, the correct result is a.