Answered

Join IDNLearn.com and start getting the answers you've been searching for. Our platform offers detailed and accurate responses from experts, helping you navigate any topic with confidence.

Solve 3x+2y=7 and x-4y=-21 by using substitution

Sagot :

Luanaidn
[tex] \left \{ {{3x+2y=7\ \ | *2} \atop {x-4y=-21}} \right. \\\\ \left \{ {{6x+4y=14} \atop {x-4y=-21}} \right.\\\\+----\\Addition\\\\ 7x=14-21\\ 7x= -7\ \ \ | divide\ by\ 7\\\\ x=-1\\ 2y=7-3x\\ y=\frac{7-3x}{2}=\frac{7+3}{2}=5\\\\Solution\ \\ \left \{ {{y=5} \atop {x=-1}} \right. [/tex]
Eahidn
3x + 2y = 7
x - 4y = - 21

6x + 4y = 14
x - 4y = - 21

6x + x = 14 - 21
7x = - 7
x = - 7 /7
x = - 1

y = (7 - 3x)/2 
y = (7 - 3 x (- 1))/2
y = (7 - (- 3))/2
y = (7 + 3)/2
y = 10/2
y = 5

Ans : x = - 1
        y = 5
We appreciate every question and answer you provide. Keep engaging and finding the best solutions. This community is the perfect place to learn and grow together. For trustworthy and accurate answers, visit IDNLearn.com. Thanks for stopping by, and see you next time for more solutions.