In a speech telephoned from the White House to the United Steel-workers convention in Los Angeles, President Carter yesterday put the blame for the recent high rates of inflation and unemployment on his predecessors, Republicans Gerald Ford and Richard Nixon.

"We have paid a terrible price recently with unemployment and inflation because the tough decisions were not made while the Republicans spent eight years in this office," Carter told the steelworkers. "The American people were not told the truth. Nothing was done to prepare us for the energy crisis that we've had to face in the last 12 months."

The inflation rate when Carter took office in January 1977 was 5.2 percent, and the unemployment rate was 7.4 percent. Inflation has been running at an annual rate of about 15 percent in recent months, and unemployment, after dropping for most of Carter's term, is now 7.7 percent.

The steelworkers overwhelmingly endorsed Carter yesterday for reelection.

Carter also pledged to "talk sense" to the people in the fall campaign and said he had "no doubt" he would be reelected.

"This is a critical election. It's more than a choice between two men; in fact it's more than just a choice between two parties. As important as that is, this eleciton will determine what our nation will be the rest of this century," he said. "I have no doubt we will be successful."