The answer to this is 169
Answer:
- r1 +4×r3 ⇒ r1
- r2 -3×r3 ⇒ r2
Step-by-step explanation:
We note that the coefficient of y in equation (iii) is 1, so it is convenient to use that equation to eliminate y from the others.
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<em>To eliminate the y-variable from equation (i), four times equation (iii) can be added to equation (i).</em>
<em>To eliminate the y-variable from equation (ii), three times equation (iii) can be subtracted from equation (i).</em>
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The result of these operations would be ...
Answer:
7+3(-4)(2)= -17
Step-by-step explanation:
7+3(-4)(2)
(-4)*2=-8
∴ 7+3(-8)= 7-24
= -17
For this case, the first thing we must do is define variables.
We have then:
n: number of cans that each student must bring
We know that:
The teacher will bring 5 cans
There are 20 students in the class
At least 105 cans must be brought, but no more than 205 cans
Therefore the inequation of the problem is given by:
Answer:
105 <u><</u> 20n + 5 <u><</u> 205
the possible numbers n of cans that each student should bring in is:
105 <u><</u> 20n + 5 <u><</u> 205
5x + y = 15
y = -5x + 15
Substituting y= -5x+15 from first equation into second equation:
3x + 2y = 16
3x + 2·(-5x + 15) = 16
3x - 10x + 30 = 16
-7x + 30 = 16
7x = 30 - 16 = 14
x = 2
Substituting x=2 into the first equation:
5x + y = 15
5(2) + y = 15
10 + y = 15
y = 15 - 10
y = 5
So your final answers are x=2 and y=5.
