# 10

Question
Systems of equations
10−3=36
2+5=−4
solve using substitution

2021-02-12
10x-3y = 36
10x = 36 + 3y
x = 3.6 + .3y
substitute x into second equation 2+5=−4
2(3.6 + .3y) + 5y = -4
7.2 + .6y + 5y = -4
7.2 + 5.6y = -4
5.6y = -11.2
y = -2
substitute y into either equation 2x + 5y = -4
2x + 5(-2) = -4
2x - 10 = -4
2x = 6
x = 3
answer: x = 3, y = -2

### Relevant Questions

Solve the matrix equation: $$4[2x,y,3z]+3[2,−4,6]=[20,−4,54]$$
Solve the matrix equation: $$\displaystyle{4}{\left[{2}{x},{y},{3}{z}\right]}+{3}{\left[{2},−{4},{6}\right]}={\left[{20},−{4},{54}\right]}$$
Solve by substitution.
y = -2x + 1
y = -6x - 11
Solve the following system again using the addition method. Multiply the appropriate equation by the appropriate factor to eliminate p, and solve for c first.
c+p=30
47c+44p=1350