Answer:
a₁₃ = - 27x - 41
Step-by-step explanation:
The nth term of an arithmetic sequence is
= a₁ + (n - 1)d
where a₁ is the first term and d the common difference
Here a₁ = - 3x + 7
d = a₂ - a₁ = - 5x + 3 - (- 3x + 7)
= - 5x + 3 + 3x - 7
= - 2x - 4
Then
a₁₃ = - 3x + 7 + 12(- 2x - 4)
= - 3x + 7 - 24x - 48
= - 27x - 41
Answer:
The side lengths are 30, 36 and 39.
Step-by-step explanation:
To find the missing side, write a proportion using side lengths from each similar shape. A proportion is an equation that sets equal two ratios.
Find y by cross multiplying numerator and denominator of each fraction.
13y = 39(12)
13y = 468
y = 36
Find the other missing side by repeating the process.
Find y by cross multiplying numerator and denominator of each fraction.
13y = 39(10)
13y = 390
y = 30
The side lengths are 30, 36 and 39.