\( A = \left[ \begin{array} { l l l } { 1 } & { 3 } & { 2 } \end{array} \right] , \quad B = \left[ \begin{array} { l } { 2 } \\ { 0 } \\ { 3 } \end{array} \right] \)

Explain how looking at a line can tell us whether its slope is negative, positive, undefined, or zero.

evidencia. \( \frac{\frac{3}{4}+\frac{y}{2}}{\frac{5}{4}}=\frac{3}{7} \)

Solve: \( -41=-9 x+4 \)

19. \( 1+2+3+4+5+\ldots+n=\frac{n(n+1)}{2} \) (a) i) Show that this formula is true for the sum of the first 8 natural numbers. ii) Find the sum of the first 400 natural numbers. (b) i) Show that \( 2+4+6+8+\cdots+2 n=n(n+1) \). ii) Find the sum of the first 200 even numbers. iii) Find the sum of the first 200 odd numbers. (c) i) Use the formula at the beginning of the question to find the sum of the first \( 2 n \) natural numbers. ii) Find a formula, in its simplest form, for \( 1+3+5+7+9+\cdots+(2 n-1) \).

\( 10 \frac { m } { s } \cdot \frac { 1 km } { 1000 m } \cdot \frac { 3600 s } { 1 h } = \)