WRITING A LINEAR EQUATION GIVEN THE SLOPE AND Y-INTERCEPT Use the equation y = mx + b The slope is the m in the equation. The b is the y-intercept in the equation. The equation of your line should be in the form y = #x + # where you have filled in for the missing #’s Slope = 5 and the y-intercept = -3 y = 5x - 3 slope y-intercept WRITING A LINEAR EQUATION GIVEN A POINT AND THE SLOPE. Use the equation y = mx + b The slope is your m in the equation. The point is your x and y in y = mx + b. The only part of the equation that you do not know is b, so you must find it. Substitute in x, y, and m into y = mx + b and solve for b. After finding b, go back to y = mx + b and substitute in the value of b and the slope. (4,5), slope = 1 4 5 = (4) + b 5=1+b -1 -1 4=b 1 4 Substitute in m and b 1 4 y= x+4 m b WRITING A LINEAR EQUATION WITH TWO POINTS Find the slope of the line with the slope equation − − Find the b value by picking one of the given points and substituting x, y, and b into y = mx + b. Substitute m and b into y = mx + b (-8, 84), (5, -46) −− + = -10 Pick point =m -46 = -10(5) + b -46 = -50 + b +50 +50 4=b Substitute in m and b y = -10x + 4

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# Writing linear equations