x = a number
7 + 2x = 21
Subtract 7 from both sides
2x = 14
Divide both sides by 2
x = 7
7 is the only number that makes this sentence true.
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.
Answer:
y = 2/3x-1
Step-by-step explanation:
The slope intercept form of a line is
y = mx+b where m is the slope and b is the y intercept
y = 2/3x +b
Using the point (-6,-5)
-5 = 2/3(-6)+b
-5 = -4 +b
Add 4 to each side
-5+4 = b
-1 =b
y = 2/3x-1
The answer is
64m^2 + 112m + 49
Answer:
12
Step-by-step explanation:
The given ratio is ...
tulips : violets = 5 : 6 = 10 : 12 . . . . . . . .multiply by 2
This tells us that maintaining the ratio will require 12 violets to be added for an addition of 10 tulips.