Answer with Step-by-step explanation:
a. The difference between 8 forty-sevens and 7 forty-sevens
Let ⊕ repesents forty- sevens.
So, Model can be represented by
8⊕ - 7⊕
=⊕⊕⊕⊕⊕⊕⊕⊕-⊕⊕⊕⊕⊕⊕⊕
=⊕
Mathematically,
let x represents forty-sevens.
So, it becomes
![8x-7x=x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/3uypiubfqm5c87imf8fgd5lte4mtngseka.png)
b. 6 times the sum of 12 and 8.
Mathematically, it is expressed as
![6* (12+8)\\\\=6* 20\\\\=120](https://img.qammunity.org/2020/formulas/mathematics/middle-school/tshn3hpuiyzzk4cgu0cq4ldmzft2okvq0k.png)
Let 12 be written as 4×3
and 8 be written as 4×2
Let ⊕ represents 4 i.e. fours.
so, there are sum of 2 fours and 3 fours.
So, it becomes,
6×(⊕⊕+⊕⊕⊕)
=6×(⊕⊕⊕⊕⊕)
=⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕
=4×30
=120