Answer:
1655
Step-by-step explanation:
Note the common difference d between consecutive terms of the sequence
d = - 1 - (- 4) = 2 - (- 1) = 5 - 2 = 8 - 5 = 3
This indicates the sequence is arithmetic with sum to n terms
=
[ 2a₁ + (n - 1)d ]
Here a₁ = - 4, d = 3 and n = 90, thus
=
[ (2 × - 4) + (89 × 3) ] = 45(- 8 + 267) = 45 × 259 = 1655
Answer:
-3 every time
Step-by-step explanation:
Answer:

Step-by-step explanation:
9 pencils cost $7.74
6 pencils cost x
The ratios are

According to the alternendo property,

Answer:
step 2
Step-by-step explanation:
The student first made an error in the step 2.
Because if we simplify the equation A in step 1, we should distribute the right side of the equation following the rule a(b-c) = a*b +a*(-c)
So, it would be
–7y = (-7)*(16)+(-7)*(-2z)
=> -7y = -112 + 14z