Step-by-step explanation:
Select all of the following that are quadratic equations.
x² + 3x - 5 = 0 ✓
x² - x = 3x + 7 ✓
5x - 7 = 0 X
7x² + 14x = 0 ✓
x³ - 3x² + 1 = 0 X
x - 5 = 9x + 7 X
What is quadratic equations?
Quadratic equations is a equation that has a general form like "ax² + bx = c"
For example :
x² + 3x - 5 = 0
x² + 3x = 5
x² → ax²
3x → bx
5 → c
Step-by-step explanation:
Since we have given that
Number of hour Marco practiced the piano on Monday is given by

Number of hours Marco practiced the piano on Tuesday is given by

1) For Adding :
Total number of hours he practiced on both Monday and Tuesday will be

2) For Subtraction,
Number of hour he practiced more on Tuesday than on Monday will be

If you have a graphing calculaator enter the matrix then on the outside of it hit the ^ button and put -1
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Answer:green area- triangle area = 72-9 = 63
Step-by-step explanation:
There are two scales that may be possible for this scale model; one where it's for every foot and one where it's for every meter.
The for every foot would be better to find out since the scale would be easier to use.
First, you have to divide each sided by 4.2, since you want to find how many meters for each foot.

For every 1 foot used in the model, the actual will be 125 meters.
1 ft = 125 m