Trying to solve Simultaneous Equations. Homework revision for an exam... These are rather easy types of simultaneous equations but when revising I found this one and i cant seem to solve it... $$19s+12t=82 \tag{1}$$ $$5s+4t=30\tag{2}$$
The point of the exercise is to find the values of t and s.
-So what I've done is label the first equation 1 and the second equation 2, as normal.
-Then I multiplied equation 2 by 3 to make the value of t the same on both equations and labelled this, new equation, equation 3: $$15s+12t=90 \tag{3}$$
-Then I took equation 3 from equation 2 to breaking it down to find the value of s.
(3) - (2)
$$4s=8$$ $$s=2$$
-So, at this point I have worked out that s=2.
-The problem, for me, is when I substitute the value of s back into equation 1. the value of t is a recurring number of 6.
-Have i done something wrong?
$4s=-8$
$s=-2$
Put value in equation (1) or (2)
$t=10$