Answer:
All expressions are correct
Step-by-step explanation:
9z+7z = 16 z
We need to find an expression ( or expressions ) that are equal to 16z
6z+3z+ 7z = 16z Correct
z+8z+7z = 16z Correct
z*16 = 16z Correct
21z+ -5z = 16z Correct
Answer:
Carlos has practiced piano for 
hours.
Carlos needs to practice 
hours.
Step-by-step explanation:
We have been given that Carlos wants to practice piano 2 hours each day. He practices piano for 3/4 hour before school and 7/10 hour when he gets home.
First of all, we will find piano practiced before school and after school by adding both amounts as:
Make a common denominator:
Add numerators:
Therefore, Carlos has practiced piano for hours.
Now, we will subtract from 2 find number of hours Carlos needs to practice to reach his goal.
Therefore, Carlos needs to practice hours before going to bed in order to meet his goal.
Represent
d=number of dimes
q=number of quarters
thererfor
q+d=23
1q=0.25
1d=0.10
therefor
total value=3.35=0.25q+0.1d
so we have
q+d=23
0.25q+0.1d=3.35
solve
q+d=23
subtract q from both sides
d=23-q
subsitute
0.25q+0.1(23-q)=3.35
distribute
0.25q+2.3-0.1q=3.35
group like terms
0.25q-0.1q+2.3=3.35
add like terms
0.15q+2.3=3.35
subtract 2.3 from both sides
0.15q=1.05
multipliy both sides by 100 to get rid of decimal
15q=105
divide both sides by 15
q=7
subsitute
q+d=23
7+d=23
subtract 7
d=16
7 quarters
16 dimes
Answer:
384
Step-by-step explanation:
8 x 6 = 48
48 x 2 = 96
12 x 10 = 120
6 x 12 = 72
8 x 12 = 96
96 + 120 + 72 +96 = 384
