Notice that the two minus signs cancel out, so 12-(-5) is equivalent to 12+5. This sum is clearly 17.
Answer:
Step-by-step explanation:
ax² + bx + c = a(x -
)(x -
)
D = b² - 4ac
= ( - b ± √D ) / 2a
~~~~~~~~~~~~
Let x² = y , then y² + 8y - 9
Find the roots of equation y² + 8y - 9 = 0
D = 64 + 36 = 100 = 10²
= ( - 8 - 10) / 2 = - 9
= ( - 8 + 10) / 2 = 1
y² + 8y - 9 = (y - 1)(y + 9) = (x² - 1)(x² + 9)
x² = 1 ⇒
= ± √1
+ 8x² - 9 = (x - 1)(x + 1)(x² + 9)
The red arrows mean the lines are parallel. Since all angles are equal, the larger triangle is similar to the smaller one. Then corresponding sides have the same ratio
(4x -2)/9 = (3x+2)/12
x(4/9 -3/12) = (2/12) +(2/9)
x = (7/18)/(7/36) = 2 . . . . . . . . . corresponding to the 3rd selection
Answer:
To calculate the gradient of a straight line we choose two points on the line itself. The difference in height (y co-ordinates) ÷ The difference in width (x co-ordinates).
so it is 0.2
Answer:
m<D=50
Step-by-step explanation:
The reason is that ABOC is a quadrilateral, so its angle add up to 360*. Each of the tangent angles, <ABO and <ACO, has a measure of 90*.
m<ABO + m<ACO + m<A + m<O = 360
90 + 90 + m<A + m<O = 360
m<A + m<O = 180
80 + m<O =180
m<O = 100
If the measure of central angle <O is 100*, what is the measure of inscribed <D?
The measure of a central angle is equal to the measure of the arc it intercepts. If m<O = 100*, then m BC = 100.
The measure of an inscribed angle is half of the measure of the arc it intercepts. If m BC = 100*, then m<D = 50
m<D=50