90 + 12/5 x 60=90 + 144 +100= 334
so 334 would be your answer
total length of the boards = 4 1/2 meters
Given:
number of boards = 5
length of each board = 9/10 meters
5 * 9/10 = (5*9)/10 = 45/10
Simplify fraction:
45/10 = 4 5/10 or 4 1/2 meters.
10 is the answer.
You know that there are 4 numbers and you have to add the numbers then divide them by four to get the mean. So all you have to do is reverse the steps, multiply 30 by 4 to get 120, then add 12+50+48 to get 110. Then subtract, 120-110=10. To check if it is correct add 12, 50, 48, and 10 to get 120, then divide by 4 to get 30. And voila, there is the answer. I hope this helped for future problems like this one.
I got 3.75. not sure if it’s right but hope i helped
Step 1) Solve the second equation for
x
:
x
+
3
y
=
−
5
x
+
3
y
−
3
y
=
−
5
−
3
y
x
+
0
=
−
5
−
3
y
x
=
−
5
−
3
y
Step 2) Substitute
−
5
−
3
y
for
x
in the first equation and solve for
y
:
3
(
−
5
−
3
y
)
−
2
y
=
7
−
15
−
9
y
−
2
y
=
7
−
15
−
11
y
=
7
15
−
15
−
11
y
=
15
+
7
0
−
11
y
=
22
−
11
y
=
22
−
11
y
−
11
=
22
−
11
−
11
y
−
11
=
−
2
y
=
−
2
Step 3) Substitute
−
2
for
y
in the solution to the second equation at the end of Step 1 and calculate x:
x=−5−(3×−2)
x=−5−(−6)
x=−5+6
x=1
The solution is x=1 and y=−2
