a.) you start with 19=h/3-8 so you add 8 to both sides then you simplify 19+8 to 27 so the equation then becomes 27=h/3 from there you multiply each side by 3 so its 27*3=h then you simplify 27*3 which leaves you with 81=h u then switch it around and your final answer h=81
b.) you start with 0.6x +0.8=1.4 first you subtract 0.8 from both sides so the equation is 0.6x=1.4-0.8 then you simplify 1.4-0.8/ so it then becomes 0.6x=0.6 u then divide both sides by 0.6 so the equation is now x=0.6/0.6 you then simplify 0.6/0.6 so you are left with x=1
Its 51, the numbers add 2 each time so 9 to 11 is 2 then you add 2 more for the next so 11 to 15 is 4 and so on
We assume the question is intended to say there are a total of 20 quarters, nickels, and dimes, the value of which is $2.05. The number of dimes is 3 times the number of quarters.
Let q, n, d represent the numbers of quarters, nickels, and dimes, respectively. Then you have three equations in the unknowns:
q +n +d = 20
25q +5n +10d = 205
-3q +d = 0
A calculator can give the solution to this matrix equation in short order. It is
q = 3
n = 8
d = 9
There are 3 quarters, 8 nickels, and 9 dimes.
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If you use the third equation to write an expression for d, you can substitute that into the other two equations.
q +n +3q = 20
25q +5n +10(3q) = 205
Simplifying, these are
4q +n = 20
11q +n = 41
Subtracting the first from the second, we find
7q = 21
q = 3
From there, it is easy to find d=9, n=8.
