Multiply 2x-5y= -21 by 3 to make it 6x-15y= -63
Multiply 3x-3y= -18 by -5 to make it -15x+15y=90
This cancels the y’s out which leaves us with
6x=-63
&
-15x=90
x for 6x=-63 equals - 10.5 so x is - 10.5 and for -15x=90, x= -6
Then you plug in x into any equation you’d like to find y.
Let’s plug in - 10.5 into 6x... equation.
6(- 10.5)-15y=-63
63-15y= -63
-63 -63
-15y=0
y=0 and x= - 10.5. When you plug in this values it makes the equation true!
But the correct answer is the first one north. Sorry if I’m doing too much hahah
If I’m confusing here’s the right answer...
6x-15y= -63
-15x+15y=90
I think it’s 5. I’m not sure
Answer:
Step-by-step explanation:
Put the value where the variable is and do the arithmetic. It can save some steps to simplify the expression first.
35 -c³ +8 = 43 -c³
<u>c = 1</u>
43 - 1³ = 43 -1 = 42
<u>c = 2</u>
43 - 2³ = 43 -8 = 35
<u>c = 3</u>
43 -3³ = 43 -27 = 16
The values that go in the blanks are 42, 35, 16.
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<em>Additional comment</em>
It does not take long to learn how to use a spreadsheet for evaluating the same formula with a number of different values of the variable(s). Graphing calculators can do this, too. It is always appropriate to use the right tool for the job.
Familiarity with multiplication and addition facts is a very good place to start. It is also useful to memorize the squares and cubes of small integers. The latter are needed here.