+0

# GELP ME

0
309
1

so i was stuck at a question and i dont know how to do it

6a + b = 16
5a - 2b = 19

Guest Jun 17, 2015

#1
+18829
+10

6a + b = 16
5a - 2b = 19

$$\small\text{ \begin{array}{lrcl} (1) & 6a + b &=& 16 \qquad | \qquad -6a\\ & \mathbf{b} &=& \mathbf{16 -6a} \\ \\ \hline \\ (2) & 5a - 2b &=& 19 \qquad | \qquad \mathbf{b} = \mathbf{16 -6a}\\ & 5a -2(\mathbf{16 -6a}) &=& 19 \\ & 5a -32 + 12a &=& 19 \\ & 17a -32 &=& 19 \qquad | \qquad +32\\ & 17a &=& 19 +32\\ & 17a &=& 51 \qquad | \qquad :17\\ & a &=& \dfrac{51}{17} \\ & \mathbf{a} & \mathbf{=} & \mathbf{3} \\ \\ \hline \\ & b &=& 16- 6a \qquad | \qquad \mathbf{a} = \mathbf{3} \\ & b &=& 16 - 6 \cdot \mathbf{3} \\ & b &=& 16 - 18 \\ & \mathbf{b} &\mathbf{=} & \mathbf{-2} \\ \\ \hline \\ \end{array} }}$$

heureka  Jun 17, 2015
Sort:

#1
+18829
+10

6a + b = 16
5a - 2b = 19

$$\small\text{ \begin{array}{lrcl} (1) & 6a + b &=& 16 \qquad | \qquad -6a\\ & \mathbf{b} &=& \mathbf{16 -6a} \\ \\ \hline \\ (2) & 5a - 2b &=& 19 \qquad | \qquad \mathbf{b} = \mathbf{16 -6a}\\ & 5a -2(\mathbf{16 -6a}) &=& 19 \\ & 5a -32 + 12a &=& 19 \\ & 17a -32 &=& 19 \qquad | \qquad +32\\ & 17a &=& 19 +32\\ & 17a &=& 51 \qquad | \qquad :17\\ & a &=& \dfrac{51}{17} \\ & \mathbf{a} & \mathbf{=} & \mathbf{3} \\ \\ \hline \\ & b &=& 16- 6a \qquad | \qquad \mathbf{a} = \mathbf{3} \\ & b &=& 16 - 6 \cdot \mathbf{3} \\ & b &=& 16 - 18 \\ & \mathbf{b} &\mathbf{=} & \mathbf{-2} \\ \\ \hline \\ \end{array} }}$$

heureka  Jun 17, 2015

### 17 Online Users

We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.  See details