Answer: x=20
all angles in the triangle are 180 degree, so:
2x+3x+4x=180
9x=180
divide both sides by 9
x= 20
2.8 = 2 + 0.8
*let's analyze the decimal 0.8 as a fraction
0.8 = 8/10
*but if we divide the numerator and denominator by the same common factor of 2, we find that the fraction can be reduced to:
(8/2)/(10/2) = (4)/(5) = 4/5
*now evaluating the whole value of 2 (from the 2.8), we know there are a total of (5) - fifths in order to make a whole, so for 2 whole, we require:
2*(5/5) = (2*5)/5 = 10/5
*Now we add the fractions together:
2 = 10/5
0.8 = 4/5
10/5 + 4/5
*add numerators only, the denominator stays as a 5
(10 + 4)/5 = 14/5
*there are no common factors between 14 & 5 (other than 1, but that won't help reduce the fraction any), so the fraction is in it's simplest form:
answer is: 14/5
Multiplying a negative number and another negative number makes the product positive.
So (-2.1)*(-1.4) = 2.94
