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krek1111 [17]
3 years ago
14

Follow the directions to solve the system of equations by elimination. 8x + 7y=39 4x – 14y = -68​

Mathematics
1 answer:
harina [27]3 years ago
8 0

Step-by-step explanation:

Hey there!

Here;

The equations are;

8x + 7y = 39.......(i)

4x - 14y =  - 68..........(ii)

Multiplying equation (i) by 2.

16x + 14y = 78

<u>4</u><u>x</u><u> </u><u>-</u><u> </u><u>1</u><u>4</u><u>y</u><u> </u><u> </u><u> </u><u>=</u><u> </u><u>-68</u>

20x = 10

x =  \frac{10}{20}

x = 1/2.

Putting value of 'x' in equation (i).

8 \times  \frac{1}{2}  + 7y =  39

4 + 7y = 39

7y = 3 9 - 4

y =  \frac{35}{7}

Therefore the value of y is 5.

<u>Check</u><u>:</u>

<u>Put</u><u> </u><u>value</u><u> </u><u>of</u><u> </u><u>x</u><u> </u><u>and</u><u> </u><u>y</u><u> </u><u>in</u><u> </u><u>equation</u><u> </u><u>(</u><u>i</u><u>)</u><u>.</u>

8x + 7y = 39

8 \times  \frac{1}{2}  + 7 \times 5 = 39

4 + 35 = 39

39 = 39

(True).

<u>Therefore</u><u>, </u><u>the</u><u> </u><u>solution</u><u> </u><u>is</u><u> </u><u>;</u><u> </u><u>(</u><u>1</u><u>/</u><u>2</u><u>,</u><u>5</u><u>)</u><u>.</u>

<em><u>Hope it helps</u></em><em><u>.</u></em><em><u>.</u></em><em><u>.</u></em>

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