Pls explain and will mark as brainliest

x = -5

Step-by-step explanation: The green x's represent positive x's, the yellow 1s represent positive numbers, and the red 1s represent negative numbers. So if you count everything your equation should look like 5x + 4 = -21. First you want to do the opposite of the plus 4, which is subtracting 4. That way the x is by itself on the left side of the equal sign. But what you do to one side you have to do to the other. So then you subtract 4 from -21. But because 21 is already negative it would equal -25. Now your equation should look like 5x = -25. Just divide by 5 for both sides and your x equals -5.