Question

Tamara rewrote the expression 0.2(4+1.4y - 2.1). Her steps are shown.

Step 1: 0.2(4+1.4y - 2.1)
Step 2: 4.2+1.6y-1.9
Step 3: 4.2-1.9+1.6y
Step 4: 2.3+1.6
Which statement identifies and explains the first mistake Tamara made?

Please helppp

Answer 1

Her first mistake was in Step 2. She added 0.2 to each term instead of multiplying by 0.2.

Explanation:

CORRECT WAY:

0.2(4+1.4y - 2.1)

0.8 + 0.28y - 0.42

0.8 - 0.42 + 0.28y

0.38 + 0.28y

WHAT TAMARA DID:

0.2(4+1.4y - 2.1)

How she got 4.2: 0.2 + 4 = 4.2

How she got 1.6y: 0.2 + 1.4y = 1.6y

How she got -1.9: 0.2 + -2.1 = -1.9

WHAT SHE DID HERE IS WRONG. REMEMBER WHEN IT IS __( ______) IT MEANS THAT YOU NEED TO MULTIPLE NUMBER OUTSIDE THE PARATNESS TO EVERY NUMBER THAT IS INSIDE THE PARATNESS.