So first you set it up in a equation. You put the amount she put in the bank over x (the x represents her full salary) which equals the percent she already spent over her full salary. That would be 120/x=30/100 you would then cross-multiply to get 12,000 = 30x. you then divide 30 from both sides to get x =400.
Step-by-step explanation: The standard form for linear equations in two variables is Ax+By=C. For example, 2x+3y=5 is a linear equation in standard form. When an equation is given in this form, it's pretty easy to find both intercepts (x and y).