Answer :
x = 53.85
Step by step explanation:
If 78% of x (some numbers) is equal to 42, then we must set this as an equation to find it.
1) Rewriting 78% as a fraction and considering that when we say 78% of some number (x) we mean a product.
78% = 78/100 ➡️ 78/100x = 42
2) Then we can go on :
100 * 78/100x = 42 * 100
78x = 4200
78x/78 = 4200/78 ➡️ x = 53.85
3) Alternatively, simply dividing 42 by 0.78 (78%) would come to the same result :
42/0.78 = 53.85
<span>6x^2y + 8x^2 − 30y − 40
= 2x^2(3y + 4) - 10(3y + 4)
= (2x^2 - 10)(3y + 4)
= 2(x^2 - 5)(3y + 4)</span>
Answer:
the answer for question 1 is -7
X + y = 1
x + 3y = 9
Subtract the second equation from the first.
-2y = -8
divide both sides by -2
y = 4
Plug 4 back into either equation and solve for x.
x + y = 1
x + 4 = 1
subtract 4 from each side
x = -3
(-3, 4)
