Question

Show that 4(m + 7) + (m + 3)^2 = (m + 3)(m + 7) + 16

Answer 1

Step-by-step explanation:

$4(m+7)+(m+3)^2=(m+3)(m+7)+16\\\\L_S=4(m+7)+(m+3)^2\\\\\text{use the distributive property}:a(b+c)=ab+ac\\\text{and formula}:\ (a+b)^2=a^2+2ab+b^2\\\\L_S=(4)(m)+(4)(7)+m^2+2(m)(3)+3^2\\\\L_S=4m+28+m^2+6m+9\qquad\text{combine like terms}\\\\L_S=m^2+(4m+6m)+(28+9)\\\\L_S=m^2+10m+37$

$R_S=(m+3)(m+7)+16\\\\\text{use FOIL}:(a+b)(c+d)=ac+ad+bc+bd\\\\R_S=(m)(m)+(m)(7)+(3)(m)+(3)(7)+16\\\\R_S=m^2+7m+3m+21+16\qquad\text{combine like terms}\\\\R_S=m^2+(7m+3m)+(21+16)\\\\R_S=m^2+10m+37\\\\\boxed{L_S=R_S}$