59.1k views
1 vote
Solve the system: 7x+2y=0 4y+9x=10

User LobsterBaz
by
3.0k points

2 Answers

5 votes
check photo for steps and answers (i boxed it)
Solve the system: 7x+2y=0 4y+9x=10-example-1
User QuickPrototype
by
4.0k points
3 votes

Answer:

{x,y} = {-2,7}

Explanation:

// Solve equation [2] for the variable y

[2] 4y = -9x + 10

[2] y = -9x/4 + 5/2

// Plug this in for variable y in equation [1]

[1] 7x + 2•(-9x/4+5/2) = 0

[1] 5x/2 = -5

[1] 5x = -10

// Solve equation [1] for the variable x

[1] 5x = - 10

[1] x = - 2

// By now we know this much :

x = -2

y = -9x/4+5/2

// Use the x value to solve for y

y = -(9/4)(-2)+5/2 = 7

Solution :

{x,y} = {-2,7}

User David Spector
by
3.2k points