How do you solve the following system?: 16x+13y=7,19x+15y=2

2 Answers
Apr 25, 2018

x=1317

y=204791

Explanation:

  1. 16x+13y=7
  2. 15y19x=2

In equation 1, make y the subject.

13y=716xy=716x13

Inject that into equation 2.

15(716x13)19x=2

Solve for x.

105240x1319x=2

105240x13=19x2

105240x=247x26

247x240x=105+26

7x=131

x=1317

Inject the value x into the rearranged equation 1 to calculate the value of y.

y=716(1317)13

y=204791

Apr 25, 2018

x=131487
y=101487

Explanation:

16x+13y=7
19x+15y=2

Multiply top equation by 15 and second linear equation by 13 to make the values of y the same so they cancel out when subtracted from each other:

240x+195y=105
247x+195y=26
which gives:
487x=131 when subtracted from each other.
x=131487

Substitute x into first original equation:

16(131487)+13y=7
(2096487)+13y=7
13y=7(2096487)
13y=(1313487)
y=(1313487)13
y=101487