We can solve this by elimination, in order to do this we need to multiply the bottom equation by three to cross out the X
(x+5y=38)3 3x+15y=114
-3x+4y=95
3x+15y=114
then add the two equations together and the X will cancel out
19y=209
----- -----
19 19
y=11
then plug that in into one of the equations
x+55=38
-55 -55
x= -17
your answer is (-17,11)
Answer:
It takes <u>8 4/7 </u>days for both bricklayers to build the wall together.
Step-by-step explanation:
The first bricklayer takes 15 days to build the wall, which means it builds 1/15 of the wall per day.
The second bricklayer takes 20 days to build the wall, which means it builds 1/20 of the wall per day.
So if they build the wall together, the expression below will tell how much of the wall they build per day together.
1/15 + 1/20
To add the fractions, we must find a common denominator, which is 60.
4/60 + 3/60, which equals 7/60.
So, they can build 7/60 of the wall per day together. How many days will it take them? We must find how many times 7 fits into 60, which can be done by solving 60/7, which is 8 4/7.
So, it takes 8 4/7 days for both bricklayers to build the wall together.
Answer: 5/6 inch/minute
Whenever you are working with a question of rate where two different quantities are being compared, the required units will indicate which quantity is to be divided by which.
In this case you want to know inches per minute.Therefore:
5
8
inches
÷
3
4
minute
5
8
÷
3
4
=
5
8
×
4
3
←
multiply by the reciprocal
=
5
8
2
×
4
3
=
5
6
Answer:
(x² - 7)(x² - 4)
Step-by-step explanation:
We can actually factor this the same way we would solve a normal quadratic equation. We will end up with the factored terms have squares of x instead of just x.
x⁴ - 11x² + 28
= x⁴ - 4x² - 7x² + 28
= x²(x² - 4) - 7(x² - 4)
= (x² - 7)(x² - 4)
