Respuesta :
1) 7(y + 3) = 5y + 8
distributing,
7(y) + 7(3) = 5y + 8
7y + 21 = 5y + 8
5y is adding on the right, then it will subtract on the left
21 is adding on the left, then it will subtract on the right
7y - 5y = 8 - 21
2y = -13
2 is multiplying on the left, then it will divide on the right
y = -13/2
2) 4(3r + 5) = -8(2r + 1)
distributing,
4(3r) + 4(5) = -8(2r) + 8(1)
12r + 20 = -16r + 8
16r is subtracting on the right, then it will add on the left
20 is adding on the left, then it will subtract on the right
12r + 16r = 8 - 20
28r = -12
r = -12/28
r = -3/7
3)
[tex]\frac{19}{4}-\frac{7}{2}a=-\frac{1}{4}a+\frac{3}{2}[/tex]7/2a is subtracting on the left, then it will add on the right
3/2 is adding on the right, then it will subtract on the left
[tex]\begin{gathered} \frac{19}{4}-\frac{3}{2}=\frac{1}{4}a+\frac{7}{2}a \\ \frac{19-3\cdot2}{4}=\frac{1+7\cdot2}{4}a \\ \frac{13}{4}=\frac{15}{4}a \end{gathered}[/tex]15/4 is multiplying on the right, then it will divide on the left
[tex]\begin{gathered} \frac{13}{4}\cdot\frac{4}{15}=a \\ \frac{13}{15}=a \end{gathered}[/tex]