The GPA is calculated as an average of the grade values weighted by its credits.
If ci is the credit and Vi is the value, the equations is the following:
[tex]GPA=\frac{\sum^{}_ic_iV_i}{\sum^{}_ic_i}[/tex]The values are:
Math:
c1 = 3
G1 = A -> V1 = 4.0
Biology:
c2 = 4
G2 = B- -> V2 = 2.7
Spanish:
c3 = 3
G3 = C+ -> V3 = 2.3
So:
[tex]GPA=\frac{\sum^{}_ic_iV_i}{\sum^{}_ic_i}=\frac{c_1V_1+c_2V_2+c_3V_3}{c_1+c_2+c_3}=\frac{3\cdot4.0+4+2.7+3\cdot2.3}{3+4+3}=\frac{12+10.8+6.9}{10}=\frac{29.7}{10}=2.97[/tex]