Substitution is where we first Isolate one of the unknowns, express it in terms of the other unknown, and replace the isolated unknown with the other unknown in another equation. So that each time we only need to deal with one unknown. I think you'll get a better idea here:
First name these 2 equations with 1 and 2.
4x + 5y = 7 (1)
y = 3x + 9 (2)
Since y is already isolated in (2), so we can skip the isolation step and continue to substitute.
Substitute (2) into (1).
4x + 5(3x+9) = 7
Expand.
4x + 15x + 45 = 7
Group.
19x + 45 = 7
Shift +45 to the other side and turn it into -45.
19x = 7 - 45
19x = -38
Shift x19 to the other side, turn it into /19.
X = - 38/19
X = - 2
Now we solved x already, we can just substitute x= - 2 back to equation (2).
y = 3(-2) + 9
y = - 6 + 9
y = 3
So, the answers are
x = - 2
y = 3
Answer:
Step-by-step explanation:
y + 2 = 12(x - 3)
y + 2 = 12x - 36
y =12x - 38
Step-by-step explanation:
please i work on by paper worksheet, see it
how can i work it
Answer: -1.7
Step-by-step explanation:
Given : Another home business has an average income of $1.200.00 per month with a standard deviation of $100.00.
i.e.

Let x represents the monthly income.
Since . 
For x= 1030 , we have

Hence, the required z-score = -1.7
2a) there is a right angle on T so 180-90-37=53
2b) do pythogrean theorem 22sq+ 12sq= 628 sq rt of 628 is 25.06 which is 25
5a) 5*8=10x so X=4
5b) 47*2=94 -57 = 37