Step 1: multiply both sides of the equation by d. d (-3) + 4ad = 2r. Step 2: subtract d(-3) from both sides. 4ad = 2r - d (-3). Step 3: multiply two factors together. Multiply - 1 and -3 to get 3. Step 4: the equation is in standard form. 4da = 2r + 3d. Step 5: undo multiplication by dividing both sides by one factor. Divide both sides by 4d. 4da/ 4d = 2r + 3d/ 4d. Step 6: undo multiplication. Dividing by 4d undoes the multiplication by 4d. a = 2r + 3d/ 4d. Last step, step 7: divide 2r + 3d by 4d. a = r/2d + 3/4. So, a = r/2d + 3/4, d ≠ 0.
PLS BRAINLIEST!!
