Answer:
C, -2
Step-by-step explanation:
-4x + 7 = 2y - 3
-4x + 10 = 2y
-2y = 4x - 10
y = -2x + 5
Answer:
20
Step-by-step explanation:
x - 9 = 11
+9 +9
x = 20
Let x be the amount of cement and y be the amount of sand. If <span>the ratio of cement to sand for mortar is 1:3, then

and y=3x.
</span>
So, if <span>Sandy puts in x=7 shovels of cement, then she puts

shovels of sand.
</span><span>
</span><span>
Answer: 21 shovels of sand.
</span>
Answer:
The second one
Step-by-step explanation: