Please help.

Solve the System of Equations by Graphing

y=4

3x+4y=4

What situation is an example of an observational study

Melissa is purchasing a $160,000 home and her bank is offering her a 30-year mortgage at a 4.9% interest rate. in order to lower her monthly payment, melissa will make a 20% down payment and will purchase 3 points. what will her monthly mortgage payment be? a. $645.98 b. $650.46 c. $662.93 d. $606.69

The dimension of the rectangular pool shown below are 40 yards by 20 yards