I think
This is your typical algebra question where you are looking for an unknown value given some information. The information can be set up as:
8 - x = 4*(x +3)
Distribute the 4:
8 - x = 4x + 12
Rearrange to get variables on one side:
8 - 12 = 4x + x
Simplifiy:
-4 = 5x
Isolate the variable:
-4/5 = x
8 ft= ___ inches
1 ft= 12 inches
8 ft= 12 x 8 inches
8 ft=96 inches
She has 96 inches, but she needs 100 inches. So she needs 4 more inches of lumber.
Answer:

Step-by-step explanation:


Answer:
1)0.123( bar on 3)
Let X = 0.123 ( bar on 3)
Then X = 0.1233 --------(1)
Multiply equation (1) by 100 we get,
100X = 12.33 --------(2)
Again multiply equation (2) by 10 we get,
1000X = 123.33 -------(3)
Subtract equation (2) from equation (3) we get,
1000X = 123.33
100X = 12.33
____________
900X = 111
X = 111/900
Hence,
0.123 ( bar on 3) is in the form of 111/900 which is in the form of P/Q.
-4 + -7= -11
When adding negative numbers if the are both negative then you add them. When you have a negative and a positive you subtract. In this problem they just took out the plus sign.