[tex]\begin{gathered} -8\mleft(1+x\mright)+7x \\ \text{ First we use the distributive propierty on -8(1+x)} \\ -8\mleft(1+x\mright)+7x=-8\cdot1+(-8\cdot x)+7x \\ \text{then we group x,} \\ =-8+x(-8+7) \\ \text{ and then we operate -8 + 7 =-1} \\ =-8-x \end{gathered}[/tex]
