78.00 = 59.99+0.10x
10.01=0.10x
x= 180.1 so she can send 180 texts plus the 100 free ones for a total of 280 texts
double check: 180 x 0.10 = 18.00 + 59.99 = 77.99
Substitute x with the members of the domain.
f(x) = 5x² + 4
Substitute with the domain of -4
f(x) = 5x² + 4
f(-4) = 5(-4)² + 4
f(-4) = 5(16) + 4
f(-4) = 80 + 4
f(-4) = 84
Substitute with the domain of -2
f(x) = 5x² + 4
f(-2) = 5(-2)² + 4
f(-2) = 5(4) + 4
f(-2) = 20 + 4
f(-2) = 24
Substitute with the domain of 0
f(x) = 5x² + 4
f(0) = 5(0)² + 4
f(0) = 5(0) + 4
f(0) = 0 + 4
f(0) = 4
Substitute with the domain of 1.5
f(x) = 5x² + 4
f(1.5) = 5(1.5)² + 4
f(1.5) = 5(2.25) + 4
f(1.5) = 11.25 + 4
f(1.5) = 15.25
Substitute with the domain of 4
f(x) = 5x² + 4
f(4) = 5(4)² + 4
f(4) = 5(16) + 4
f(4) = 80 + 4
f(4) = 84
The range of the function for those domain is {4, 24, 15.25, 84}
-2 yo creo que está correcto