The first 3 are examples of the difference of 2 squares so you use the identity
a^2 - b^2 = (a + b)(a - b)
x^2 - 49 = 0
so (x + 7)(x - 7) = 0
so either x + 7 = 0 or x - 7 = 0
giving x = -7 and 7.
Number 7 reduces to 3x^2 =12, x^2 = 4 so x = +/- 2
Number 8 take out GCf (d) to give
d(d - 2) = 0 so d = 0 , 2
9 and 10 are more difficult to factor
you use the 'ac' method Google it to get more details
2x^2 - 5x + 2
multiply first coefficient by the constant at the end
that is 2 * 2 = 4
Now we want 2 numbers which when multiplied give + 4 and when added give - 5:- -1 and -4 seem promising so we write the equation as:-
2x^2 - 4x - x + 2 = 0
now factor by grouping
2x(x - 2) - 1(x - 2) = 0
(x - 2) is common so
(2x - 1)(x - 2) = 0
and 2x - 1 = 0 or x - 2 = 0 and now you can find x.
The last example is solved in the same way.
Answer:
y=-2x-2
Step-by-step explanation:
Just ask.
Hope this helped! :)
[-½, ¾]; use either "Substitution" or "Elimination" to do this, and you'll see that this answer is correct.
Isolate the variable by dividing each side by factors that don't contain the variable.
x= 13/4 - y/4
If you are solving for x (only)
X = 45/4 - y/4
If you are solving for y (only)
Y= 45- 4x
Answer:
The volume of the solid will be = 134.1 cubic units.
Step-by-step explanation:
The base of a solid has the equation of a circle x² + y² = 16 in the xy-plane. Cross-sections perpendicular to the y-axis of the solid are semicircles.
Therefore, the solid will be the shape of a hemisphere.
Now, the radius of the hemisphere will be 4 units.
{Since the base of the hemisphere is on the xy-plane and have equation
x² + y² = 4²}
Therefore, the volume of the solid will be = 
cubic units. (Answer)
