Question 1169747

solve the following pair of simultaneous equations.
3/5x - 4y = -1
0.8x - 3.5y = 1/2
<pre>The other person's answers are <b><u>WRONG</b></u>!!
{{{matrix(2,6, (3/5)x - 4y, "=", - 1, "------", eq, "(i)", 0.8x - 3.5y, "=", 1/2, "-----", eq, "(ii)")}}}
When solving systems, always try to work with the smallest numbers possible
Now, to get rid of the decimals and fractions, we multiply eqs (i) & (ii) by 10 to get:
6x - 40y = - 10 --- eq (iii)
8x - 35y = 5 ------ eq (iv)
You then multiply eq (iii) by 4 and eq (iv) by 3 to get:
24x - 160y = - 40 ---- eq (v)
24x - 105y = 15 ------ eq (vi)
       55y = 55 ------ Subtracting eq (v) from eq (vi)
        {{{highlight_green(matrix(1,5, y, "=", 55/55, "=", 1))}}}
I'll leave "x" for you to find!