There is same number of pennies, nickels, and dimes in a wallet. Together they make $1.28. How many coins are there in the walle
2 answers:
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<h3>Answer:</h3>
(5, -2, -3)
<h3>Explanation:</h3>We assume your equations are ...
- x +3y -z = 2
- 4x +2y +5z = 1
- 3x +0y +z = 12
These have solution (x, y, z) = (5, -2, -3).
_____
<em>How we know</em>
Trying the choices in the last equation eliminates the first and last. Trying the second choice in the first equation eliminates it, leaving the 3rd choice as the answer you're looking for.
We also know because we can ask a graphing calculator to solve the matrix equation (or row-reduce the augmented matrix).
<em>Comment on this problem</em>
The hardest part of this problem is figuring your intent. The equations are not well-separated, so we have a hard time telling what is a constant and what is a coefficient. It took a couple of guesses to sort it out. A little editing before posting would be helpful.
Answer:
the graph on the right-top
Step-by-step explanation:
Transferring an "x" to the right side in , we get
The system of inequalities is
We have y=2x+2 - ascending function with a=2, b=2
b=2 shows that ascending function intersects Y-axis is in y=2 - that situation is only on the right-top and left-down. So, we refuse left-top and right-down.
y=-x-3 - descending function with a=-1, b=-3
y<2x+2 is an area below the ascending function and we see that on the left-
is an area above the descending function
On the left-down we have an area above both functions, so we refuse this picture
Right-top is correct
Answer:
x = 200
Step-by-step explanation:
Given
x -
y = 30 ← substitute y = 15 into the equation
x -
× 15 = 30 , that is
x - 10 = 30 ( add 10 to both sides )
x = 40 ( multiply both sides by 5 to clear the fraction )
x = 200