Answer:
3/140
Step-by-step explanation:
1/4 x 2/5 + -1/6 x 3/2 + 3/7 x 2/5
= (1/4 x 2/5) + (-1/6 x 3/2) + (3/7 x 2/5)
= 2/20 + -1/6 x 3/2 + 3/7 x 2/5
= 2/20 + -3/12 + 3/7 x 2/5
= 2/20 + -3/12 + 6/35
Now that you have multiplied all the number together you need to find the common denominator ( b in the problem a/b )
42/420 + -105/420 +
72/420
Now...
42 + 72 + -105
= 114 + -105
= 9
= 9/420
Now you have to simplify...
9/420 ÷ 3
= 3/140
