Answer:
x = 3
y = 2
Step-by-step explanation:
4x + 3(3x - 7) = 18 <em>Substitute</em><em> </em><em>y</em>
4x + 9x - 21 = 18 <em>Simply</em>
13x - 21 = 18 <em>Add</em><em> </em><em>like</em><em> </em><em>terms</em>
13x = 39 <em>Add</em><em> </em><em>2</em><em>1</em>
x = 3 <em>Divide</em><em> </em><em>by</em><em> </em><em>1</em><em>3</em>
y = 3(3) - 7 <em>Substitute</em><em> </em><em>x</em>
y = 9 - 7 <em>Simply</em>
y = 2 <em>Subtract</em>
Let's check:
4(3) + 3(2) = 18
12 + 6 = 18
18 = 18
It works!
The answer is D.
milli = 0.001
centi = 0.01
deci = 10
kilo = 1,000
Assuming you are speaking of the Real Numbers…
x^2+66=14x+15
x^2 - 14x + ?? = -51
x^2 - 14x + (half of -14 squared) = -51 + (half of -14 squared)
x^2 - 14x + 49 = -51 + 49
(x - 7)^2 = -2
By the way, in the real number system, you can’t square any number and get a negative so the above equation has no solution. If you allowed for complex solutions…there would be two of those.
Answer:
b² = a² + c² - 2ac cos B
Step-by-step explanation:
The cosine rule can be use when you are given three sides of a triangle and ask to find any angle or when you are given two sides and a included angles(the angle between the two sides given) and ask to find the length of a side.
The equation Sophia can use to solve for the side length(b) of a triangle when given two length and the included angle can be expressed below. Sophia was given two sides and an included angle and was asked to find a side length b.
For sides a, b and c the cosine rule can be represented below
a² = b² + c² - 2bc cos A
b² = a² + c² - 2ac cos B
c² = a² + b² - 2ab cos C
The equation required base on your question is
b² = a² + c² - 2ac cos B
9.50 + (2.20)r
For example if he fixed 3 watches
9.50 + (2.20)3
We plug in 3 for r and he makes 6.60 extra.