The general equation given is x^2 - 4x + y^2 = -3. Transform this to an equation of a circle of the form x^2 + y^2 = r^2.
Use completing the square method:
x^2 - 4x + 4 + y^2 = -3 + 4
(x - 2)^2 + y^2 = 1
the center of the circle is (2,0) and r = 1
To check if it intersects the y axis, find the value of the x-intercept.
Answer:
-40
Explanation:
Given
u = 2i - j; v= -5i + 4j and w = j
Required
4u(v-w)
4u = 4(2i) = 8i
v - w = -5i + 4j - j
v - w = -5i + 3j
Substitute
4u(v-w)
= 8i(-5i+3j)
= -40(i*i) [since i*i = 1]
= -40
Hence the required solution is -40
So you need to find 15% of $27.38. To do this you can multiply 27.38 * .15 and get 4.107. Round to $4.11 and this is the tip. The total bill would be $31.49