In mathematics, a polynomial<span> is an expression consisting of variables (also called indeterminates) and coefficients, that involves only the operations of addition, subtraction, multiplication, and non-negative integer exponents of variables. An example of a </span>polynomial<span> of a single indeterminate x is x</span>2<span> − 4x + 7.</span>
Let s = northbound train
Then
2s = southbound train
:
Distance = time * speed
4s + 4(2s) = 600
:
4s + 8s = 600
:
12s = 600
:
s = 600/12
:
s = 50 mph is the northbound train
Then
2(50) = 100 mph is the southbound train
:
:
Check:
4(50) + 4(100) = 600
Answer:
x = ±6
Step-by-step explanation:
x^2/4=9
Multiply by 4 on each side
x^2/4 *4=9*4
x^2 = 36
Take the square root of each side
sqrt(x^2) = ±sqrt(36)
x = ±6
