Answer:
30 dollars
Step-by-step explanation:
4(5) + 10 = 20 + 10 = 30
K = Kevin's age
D = Daniel's age
K = 3D
K - 4 = 5(D - 4)
Plug in 3D for the K values in the second equation.
3D - 4 = 5(D - 4) Use the Distributive Property
3D - 4 = 5D - 20 Add 4 to both sides
3D = 5D - 16 Subtract 5D from both sides
-2D = -16 Divide both sides by -2
D = 8
Now, plug that D value into the original equation.
K = 3D Plug in the D value
K = 3(8) Multiply
K = 24
Finally, you can double check your math.
4 years ago, Daniel would've been 4 and Kevin would be 20, so Kevin would've been 5 times as old as Daniel. And 8 x 3 = 24.
So, Kevin is 24.
I: 635=dimes*10+quarters*25
or shorter
635=d*10+q*25
II: d=q*3+3
Substitute II (d=3q+3) into I to replace d:
635=d*10+q*25
635=(3q+3)*10+q*25
635=30+30q+25q
605=55q
11=q
-> 11 quarters
"What expression represents the number of dimes if q represent quarters"
insert q=11 into II:
II: d=q*3+3
d=11*3+3
d=33+3
d=36
Ok what else before I can help