Answer:

Step-by-step explanation:
When choosing equations to write, make sure you choose a pair that allow you to isolate a variable and solve for it.
Sample solution:



Answer is provided in the image attached.
4
Step-by-step explanation:
Answer:
r=9/2 or 4.5
Step-by-step explanation:
First of all our goal is to get R by itself
by cross multiplying we get,
(r+3)*3=5r
by distributive property we get
3r+9=5r
substracting 3r from both sides we get
9=2r
by dividing by 2 in both sides we get
r=9/2 or 4.5
9xy2-6x2y+5x3. Change every sign in the equation as if you were multiplying each part by -1.