Mathematics: What is the value of y in the solution to this system of equations? 5x – 7y = 7 y = -5x + 3

What is the value of y in the solution to this system

glowbaby123

22.03.2022

y = -0.5

Step-by-step explanation:

given

5x – 7y = 7 eq 1

y = -5x + 3 (we rearrange this so that the terms are in the same order as eq 1)

-5x – y = -3 eq 2

by elimination, eq 1 + eq 2

(5x – 7y) + (-5x – y) = 7 + (-3)

5x - 7y -5x - y = 7-3

-8y = 4

y = 4/(-8)

y = -0.5

0,0(0 оценок)

rsanchez1226

16.03.2021

Step-by-step explanation:

Let the number be x.

According to the question,

$\dashrightarrow \sf { \dfrac{1}{4}x - \dfrac{1}{5}x= 8 + 10 } \\$

$\dashrightarrow \sf { \dfrac{5x + 4x}{2}= 18 } \\$

$\dashrightarrow \sf { \dfrac{9x}{2}= 18 } \\$

$\dashrightarrow \sf { 9x = 18 \times 2 } \\$

$\dashrightarrow \sf { 9x = 36 } \\$

$\dashrightarrow \sf { x =\cancel{ \dfrac{36}{9} }} \\$

$\dashrightarrow \underline{\boxed{\pmb { \frak {x = 4 }}}} \\$

The number is 4.

0,0(0 оценок)