solving equations with R

[Michael12]

How can I solve equations for a variable

e.g.
100+315/(1+r)=3.5/(1+r)+442/(1+r)^2
How can I solve this equation for r
Is there a specific function in R for this?

[technocrat]

@Michael12

100+315/(1+r)=3.5/(1+r)+442/(1+r)^2

Problems benefit from a preliminary assessment before landing on a function

suppressPackageStartupMessages({
  library(ggplot2)
})

find_result <- function(r, w, x, y, z) {
  lhe <- w+x/(1+r)
  pt1 <- y/(1+r) 
  pt2 <- z/(1+r)^2
  rhe <- pt1 + pt2
  equation <- lhe + rhe
}

x <- data.frame(test = c(1e6,1e7,1e8,1e9,1e10))

ggplot(x,(aes(test,find_result(test,100,315,3.5,442)))) +
  geom_line() +
  theme_minimal()

^{Created on 2021-01-01 by the reprex package (v0.3.0.9001)}