Expression with last digits different

arithmetic

Solution 1:

HINT : $$(x+3)(x+4)-(x+5)(x+2)=3\times 4-5\times 2$$

Solution 2:

Hint $\ a\!+\!b = c\!+\!d\,\Rightarrow\, (x\!+\!a)(x\!+\!b)-(x\!+\!c)(x\!+\!d) = ab\!-\!cd,\ $ and conversely.

Related

Easiest way to find $\Re\int_{0}^{\pi/2} e^{e^{i\theta}} d\theta$
Pythagorean theorem expressed without roots in an old Tamilian (Indian) statement
Find $\lim_{x\to \frac\pi2}\frac{\tan2x}{x-\frac\pi2}$ without l'hopital's rule.
What's the difference between uniformly equicontinuous and uniformly continuous?
Why can no prime number appear as the length of a hypotenuse in more than one Pythagorean triangle?
Adding digits to make a number prime or composite
Show integral limit
Is there only one pair of unequal rational numbers with $n^m = m^n$? [duplicate]
Improper integral of sin(x)/x from zero to infinity [duplicate]
$\mathbb{Z}$ is the symmetry group of what?
Listing methods to prove that two groups are not isomorphic
When is $ 999\cdots$ a perfect square?