X + y = 7
xy = -30
x + y = 7
x - x + y = -x + 7
y = -x + 7
xy = -30
x(-x + 7) = -30
x(-x) + x(7) = 30
-x² + 7x = -30
-x² + 7x + 30 = 0
-1(x²) - 1(-7x) - 1(-30) = 0
-1(x² - 7x - 30) = 0
-1 -1
x² - 7x - 30 = 0
x² - 10x + 3x - 30 = 0
x(x) - x(10) + 3(x) - 3(10) = 0
x(x - 10) + 3(x - 10) = 0
(x + 3)(x - 10) = 0
x + 3 = 0 or x - 10 = 0
- 3 - 3 + 10 + 10
x = -3 or x = 10
x + y = 7 or x + y = 7
-3 + y = 7 or 10 + y = 7
+ 3 + 3 - 10 - 10
y = 10 or y = -3
(x, y) = (-3, 10) or (x, y) = (10, -3)
The two numbers that add up to 7 and multiply to 30 are -3 and 10.
Answer:
b
Step-by-step explanation:
brainliest????
Answer:
3.46209 x 10^1
Step-by-step explanation:
Move the decimal so there is one non-zero digit to the left of the decimal point. The number of decimal places you move will be the exponent on the
10.
Write 4.1 as a mixed number and as an improper fraction. Do not try to simplify your answers?
Answer:
Step-by-step explanation:
As we have 1 numbers after the decimal point, we multiply both numerator and denominator by 10. So,
4.1
1
= (4.1 × 10)
(1 × 10)
= 41
10
.
(This fraction is alread reduced, We can't reduce it any further).
As the numerator is greater than the denominator, we have an IMPROPER fraction, so we can also express it as a MIXED NUMBER, thus 41
10
is also equal to 41
10
when expressed as a mixed number.