2x+4=7 subtract 4 from both sides
2x=3 divide both sides by 2
x=3/2
x=1.5
Adding a negative number is the same as subtracting a positive number. So 2315.5 - 3166.75 = -851.25
Answer:
B.) 18
Step-by-step explanation:
To find the correct b value we use this formula
b² - 4ac = 0
b = What we are solving for
a = 1
c = 81
b² - 4(1)(81) = 0
b² - 324 = 0
b² = 324

b = ±18
And 18 is one of the answer choices
So B.) 18 is the correct answer.