# Solve the following Equation: $(3{m^2} - 7)(4n + 3 - 5{m^2})$ .
Hint: Use the properly, ${a^n} \times {a^m} = {a^{n + m}}$
We have given the equation $(3{m^2} - 7)(4n + 3 - 5{m^2})$ . Observe that, we can directly start to solve by opening the brackets as follows:
$(3{m^2} - 7)(4n + 3 - 5{m^2}) \\ \Rightarrow 3{m^2} \times 4n + 3{m^2} \times 3 - 3{m^2} \times 5{m^2} - 7 \times 4n - 7 \times 3 + 7 \times 5{m^2} \\ \Rightarrow 12{m^2}n + 9{m^2} - 15{m^4} - 28n - 21 + 35{m^2} \\ \Rightarrow 12{m^2}n + 44{m^2} - 15{m^4} - 28n - 21 \\ \Rightarrow {m^2}(12n + 44 - 15{m^2}) - 28n - 21 \\$
Hence the required multiplication is ${m^2}(12n + 44 - 15{m^2}) - 28n - 21$ .