To find explicit formulas, you need two things. The common difference and the first term.
For example, #18
The first term = -15
The common difference = -20 -(-15) = -20 + 15 = -5
y = A + B(n - 1)
A = our first term
B = our common difference
n = the term you want to find in the sequence.
Leta plug our numbers in from #18
y = -15 + -5(n - 1)
Let's find the 4th term in the sequence.
y = -15 + -5(4 - 1)
y = -15 + -5(3)
y = -15 + -15
y = -30
0.3, 0.03,0.003
Because 0.3 is equivalent to 3/10
Because 0.03 is equivalent to 3/100
Because 0.003 is equivalent to 3/1000
7/6x=140
since variable x is multiplied by 7/6, find x by multiplying by the inverse of 7/6 which is 6/7.
7/6x × 6/7 = 140 × 6/7
x= 120
Answer:

Step-by-step explanation:
Well we can start by seeing if the parabola is the same width by comparing it to its parent function ( y = x^2 )
In y = x^2 the 2nd lowest point is just up 1 and right 1 away from the vertex.
This is not true for our parabola.
So we can widen it by to the desidered width by making the x^2 into a .5x^2.
So far we’ve got y = .5x^2
Now the parabola y intercept is at -5.
So we can add a -5 into the equation making it.
y = .5x^2 - 5
Now for the x value.
So we can find the x value by seeing how far away the parabola is from from the y axis.
So the x value is -2x.
So the full equation is 
Look at the image below to compare.