r + 14 = 39 r = 25
25
r = 25
R+14=39
R+14=39
39-14=25 so R=25 25+14=39
-21
39 - 14 - 6 = 19
39
x + 7y = 39 So x = 39 - 7y Substitute for x in the second equation: 3(39 - 7y) - 2y = 2 117 - 21y - 2y = 2 115 = 23y y = 5 Substitute this value for y back into the first equation: x + 7*5 = 39 x + 35 = 39 x = 4
Replace the value of a in the equation 6a+3 So 6x6+3=36+3=39.
It is a linear equation in one variable, a.