For
solving system of equations, we can use either substitution where we plug one
equation into the other, or elimination where we combine the equations.
-
Using elimination,
you would to eliminate one variable from both equations, so you automatically would
get one equation with one variable!
- Using
substitution
means you are going to solve one equation for one variable and substitute with
its value in the other equation in order to get also an equation with one
variable.
Let's take an example ...
y+x=2 and y-2x = 1
<span>Using <span>elimination, we need to subtract these two equation; one from the other...
y+x=2
-
y-2x=1
-----------
0+3x=1
then
x=1/3 and then substitute into any equation to get y-value</span></span>
y+x=2
y+1/3 = 2 >>>>>
y=5/3NOW...<span>Using substitution
</span>y+x=2 and y-2x = 1 >>(y=1+2x)
Plug (y=1+2x) into y+x=2 and solve for x
y+x=2
(1+2x) + x =2
1+3x = 2
3x=1
again (and for sure)
x = 1/3plug in x=1/3 into any of the equations above to get y:
y+x=2
y+1/3=2
y=5/3DOne !!!!!!
I hope you got
the idea
If you still need help, just let me know.
Answer:
Step-by-step explanation:
Using this rule we have:
1 12 13 14 15 16 17 18
2 23 24 25 26 27 28
3 34 35 36 37 38
4 45 46 47 48
5 56 57 58
6 67 68
7 78
8
approximately 28 pairs. (breakdown above) hope this helps
