We know that the perimeter of a rectangle is 2(width)+2(length). We can multiply the length by 2 to find out how much remaining fencing we have, then divide that number by 2 to find the width.
15.5*2=31
170.5-31=139.5
139.5/2=69.75
A possible width is 69.75 feet.
34/100
= 0.34
3 tenths, 4 hundreths
Use proportions:
height/shadow
2.6/1.24 = x/38.25
Cross multiply
1.24x=99.45
x = 80.2016129
1. 3a - 1 + 18 - a
So you can reorder these, as long as they keep the sign in front of them.
3a - a - 1 + 18, you can reorder it to.
And then just add or subtract.
2a + 17
2. (a+3) - (a + 2)
First you want to open the parenthesis.
To do that, check the symbol before the parenthesis.
If it's a minus, reverse the operator inside the parenthesis. If it's a plus, do nothing.
So just,
a + 3 - a - 2
Then reorder again
a - a + 3 - 2
1
3. 43 + a - 2a
Just subtract, a - 2a, to get -a.
So,
43 - a