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Maths Percentage (Partial) - PsyDAG, Monday, February 11, 2013 at 12:49pm
1. (1-.30)x = 140
3. C = A + 15
5C + 10A = 150
Substitute A+15 for C in second equation and solve for A. Insert that value into the first equation and solve for C. Check by inserting both values into the second equation.