90 hazelnuts = 125g
Therefore, the mass of one hazelnut is this...
90 / 90 = 125 / 90
1 hazelnut = 25/18 grams
630 calories = 100 grams
100 divided by 25/18 = 72
Therefore...
630 / 72 = 1 hazelnut
AND THE ANSWER IS
8.75 calories = 1 hazelnut
That would be :
4x – 10 = x2 – 5x + 10 ( y = 4x - 10 is substitute for y)
PROOF: y + 5x = x²<span> + 10
</span> (4x - 10) + 5x = x² + 10
4x - 10 = x² -5x + 10
<span>
</span>0 = x2 – 9x + 20<span> (liked terms are grouped and simplified)
PROOF: </span> 4x - 10 = x² -5x + 10
4x = x² -5x + 10 + 10
0 = x² -5x -4x + 20
0 = x² - 9x + 20
Solving:
x² - 9x + 20 = 0
x² - 5x - 4x + 20 = 0
(x - 5) (x - 4) = 0
⇒ x = 4 (as question says) OR x = 5
X>-4 would be the correct answer
