Question 1154218
1.3s+1.7f=37.9
5.4s+5.6f=147.2

can you send me the answers and the work if possible
<pre>Correct answers: {{{highlight_green(matrix(2,3,f, "=", 7, s, "=", 20))}}}
1.3s + 1.7f = 37.9 ------ eq (i)
5.4s + 5.6f = 147.2____2(2.7s + 2.8f) = 2(73.6)_____2.7s + 2.8f = 73.6 ----- eq (ii)

In order to avoid too many decimals and very large numbers, you can do the following:
1.4s + 1.1f = 35.7 ----- Subtracting eq (i) from eq (ii) ------ eq (iii) 
.1s - .6f = - 2.2 ------ Subtracting eq (i) from eq (iii)------ eq (iv) 
s - 6f = - 22_____s = 6f - 22 ---- Multiplying eq (iv) by 10 ---- eq (v)
1.3(6f - 22) + 1.7f = 37.9 ------- Substituting 6f - 22 for s in eq (i) 
7.8f - 28.6 + 1.7f = 37.9
9.5f = 66.5
{{{highlight_green(matrix(1,5, f, "=", 66.5/9.5, "=", 7))}}}

s = 6(7) - 22 ------ Substituting 7 for f in eq (v) 
{{{highlight_green(matrix(1,5, s, "=", 42 - 22, "=", 20))}}}
You can do the check!!