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
A = L^2
A = L^2 = 2^2 + 4^2 (Pythagorean’s theorem)
A = L^2 = 20
Therefore the area of the square is 20 units square.
Answer:
It is the longest one (20).
Step-by-step explanation:
The hypotenuse is the length opposite the right angle and between the legs. In this case it is the longest one.
it would be 6 3/8 because the common factor is 5
Answer:
Graph 1: not a function
Graph 2: is a function
Graph 3: is a function
Step-by-step explanation:
Use the vertical line test. Draw a straight line anywhere on your graph. if it passes over 2 points or more on your graph then it's not a function
