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.
It is the first one I believe
Answer:
yes correct
Step-by-step explanation:
given
5x ≥ 3x + 4 ( subtract 3x from both sides )
2x ≥ 4 ( divide both sides by 2 )
x ≥ 2 ← is the solution to the inequality
The only value greater than 2 is 3
Add them. Pentagram interior angle is 540. 105+101+112+113=431. 540-431=109 Hence, 109 is the answer. Please brainliest.
Answer:
3 + 4 = 7 which is true.
Step-by-step explanation:
Whenever you have an equation with a plain variable (that is, no exponent included), there is only one number that will work when substituted for x.
To solve it, you have to "undo" what is done to the variable. You also go in the reverse order of operations, so you do the addition/subtract first, then multiplication/division.
You also have to do the same to both sides, kind of like keeping a balance scale in balance.
In this case, we subtract 4 from both sides first:
3x + 4 -4 = 7 - 4
The + 4 - 4 cancel each other out, so you get:
3x = 3
3x means "3 times x" so you divide by 3 to undo it. I will use the / to indicate division:
3x / 3 = 3 /3
so 1x = 1.
Since 1x is "1 times x" it is the same as x by itself, so:
x=1
AND, if we substitute 1 back into the original equation (the asterisk stands for multiply):
3 * 1 + 4 = 7
3 * 1 is 3, so:
3 + 4 = 7 which is true.
1 is the only number that works.
Hope this helped.
