Answer:
7
Explanation:
−
2
x
+
10
=
−
4
take 10 from both sides
−
2
x
=
−
14
divide both sides by -2 to find x
x
=
7
Step-by-step explanation:
Answer:
One cup of coffee is $3.25
Step-by-step explanation:
Create a system of equations where c is the cost of a cup of coffee and d is the cost of a donut
2c + 4d = 10.5
c + 5d = 8.25
Solve by elimination by multiplying the top equation by -5 and the bottom equation by 4
-10c - 20d = -52.5
4c + 20d = 33
Add them together and solve for c
-6c = -19.5
c = 3.25
So, a cup of coffee is $3.25
9 dived by 3 = 3
so he surfed for 3 hours = 1/3 of 9
and there are 6 hours left
so he spent 6 hours building a sandcastle