Twice a number increased by 12 is equal to 31 less than three times the number. find the number

Which statements about these triangles is true

The salesperson earns a 5% commission on the first $5,000 she has in sales. the salesperson earns a 7.5% commission on the amount of her sales that are greater than $5,000. this month the sales person had $8,000 in sales. what amount of commission, in dollars, did she earn?

47: 4 aisha changed 1.45 + 2.38 to 1.5 + 2.4 in order to estimate the sum. what estimation method did she use?