Answer:
(- 2, 3 )
Step-by-step explanation:
Given the 2 equations
x + y = 1 → (1)
2y - x = 8 → (2)
Adding the 2 equations term by term will eliminate the x- term
(x - x) + (y + 2y) = (1 + 8), that is
3y = 9 ( divide both sides by 3 )
y = 3
Substitute y = 3 into either of the 2 equations and solve for y
Substituting y = 3 in (1)
x + 3 = 1 ( subtract 3 from both sides )
x = - 2
Solution is (- 2, 3 )
Answer:
The answer is A.
Step-by-step explanation:
If an integer is both a square and a cube, it can be of the form:
<span>(<span>a3</span><span>)^2</span></span>
Now,
since a cube can be of the form 7k or 7k+-1(thanks to FoolForMath),
we write
<span><span>a^3</span>=7k</span>
and get the no to be
49k^2
, which is in the form of 7 times something
<span>49<span>k^2</span>=7×(7<span>k^2</span>)</span>
Now put
<span><span>a^3</span>=7k+−1</span>
Square it
and you'll get a number in the form of (7times something +1)
