That's far more problems than I usually accept in a single question, but since you're new and obviously a beginner, I'll try to help.
To Increase an amount by 7% what single multiplier would you use
We want 7% more than 100% of the amount, so the multiplier is
(100% + 7%) = 107% = 1.07
[Remember that "percent" means "per hundred," so we divide a percentage by 100 to get the numerical equivalent.]
To Decrease an amount by 7% what single multiplier would you use
We want 7% less than 100% this time, so the multiplier is
(100% - 7%) = 93% = 0.93
5 ÷ 0.1
= 50
(To One Decimal Place) (0.3 x 2.8)Squared
[Notation: around here we usually write "squared" as ^2, where the ^ is an exponentiation sign.]
(0.3 x 2.8)^2 = 0.84^2 = 0.7056
which is 0.7 when rounded to one decimal place.
6.38 + 4.52 ÷ 4.71 +9.53
= 6.38 + (4.52 ÷ 4.71) + 9.53 [assuming operations in the usual order]
= about 6.38 + 0.96 + 9.53
= 16.87
Expand and Simplify
(x + 2)(x + 3)
= x^2 + 2x + 3x + 6
= x^2 + 5x + 6
Expand and Simplify
(x + 2)(x - 3)
= x^2 + 2x - 3x - 6
= x^2 - x - 6
x + 1 < 5
x < 4 [subtracting 1 from both sides]
Make n the subject of the formula.... M=3n
3n = M
n = M/3